1. Field of the Invention
The present invention relates to a chip inductor which uses a sintered magnetic core and also relates to a method of manufacturing the same.
2. Description of Related Art
Conventionally, there is known a method of manufacturing a chip inductor, characterized in that: a kneaded material to be obtained by kneading a powdered magnetic material (or magnetic substance) and a binder is pressurized to form it into a rectangular parallelepiped or a cylindrical body and thereafter sinter it to manufacture a bar of the magnetic material; a conductor (or a conducting wire) is wound around the bar of the magnetic material to thereby mount a coil in a coiled manner; terminals of the coil are extended to end surfaces of the bar of the magnetic material to thereby connect them to external terminals which are formed on the end surfaces of the bar of the magnetic material; the coil is then covered or coated with the kneaded material of the powdered magnetic material and the binder to thereby form an external cover (or coating); and thereafter a semimanufactured product thus obtained is sintered.
In the above-described chip inductor, the coil is covered with the magnetic material. Therefore, a circular magnetic circuit is formed in a manner to enclose the coil, with the result that an inductance value is high and that there is little or no magnetic field to leak outside the magnetic material. It has consequently an advantage in that, even if the chip inductor is disposed in close proximity to other parts, there will be no influence on the characteristics as an inductor and therefore that a density of mounting parts on a wiring circuit board or the like can be made higher.
However, this kind of inductor has a disadvantage in that, when a large pulse electric current is caused to flow therethrough, there is likely to occur a breaking at the connecting portions between the external electrodes and the terminal ends of the coil.